Structural and magnetic properties of a stage-2 HoCl3-graphite intercalation compound

A stage-2 HoCl3-GIC has been synthesized and characterized by XRD experiments and magnetic measurements. EDS and 00l X-ray analyses lead to the chemical formula C23.8HoCl3.7.The c-axis repeat distance is 1313 ± 5 pm, and the stacking sequence of intercalated HoCl3 along the c-axis corresponds to the layer sandwich Cl–Ho–Cl, where the distance between Ho and Cl layers is 157 pm. The HoCl3 in-plane structure is oblique with lattice parameters a = 689 pm, b = 1177 pm, γ = 149.6° close to those in the pristine crystal. It presents two different micro-domains disorientated with respect to graphene planes by θ1 = ± 19°. Magnetic studies show that Ho3+ ions obey the Curie–Weiss law for both pristine HoCl3 and stage-2 HoCl3-GIC. The presence of graphene planes between HoCl3 intercalated layers leads to an increased Curie–Weiss temperature and to a decrease in the weak antiferromagnetic interactions between Ho3+ ions.